Process for producing alkaline earth metal sulfonates



PRocnss non PRODUCING ALKALINE EARTH METAL SULFONATES Manu'el Bluiner, Petrolia, Pa., assignor to Sonnebom Chemical and Refining Corpration, a corporation of Delaware No Drawing. Filed Sept. 6, 1956, 'Ser. No. 608,205

r 11 Claims. (Cl. 252-33) This invention is a new and useful process for produc-' ing the alkaline earth metal sulfonates of oil-soluble mahogany sulfonic acids in commercially pure form and in systems consisting in part of such sulfonates and in part of hydrocarbon oil. alkaline earth metal includes magnesium.

Sulfonic acids are formed when a petroleum distillate is treated with fuming sulfuric acid or sulfur trioxide. A part of these (the so-called green sulfonic acids) together with unconsumed sulfuric acid separate out as a sludge layer, leaving the other sulfonic acids (the so-called mahogany acids) in solution in the acid-treated oil, which also contains as impurities sulfuric acid and sulfur dioxide. These mahogany sulfonic acids are presumably the reaction products of alkyl arenes occurring naturally in the distillate since similar acids result from the treatment of synthetic alkyl arene hydrocarbons with fuming sulfuric acid or sulfur trioxide.

Alkaline earth metal sulfonates of such mahogany sul-' fonic acids in oil solution can be obtained by neutralizing the sulfonic acids in solution in a hydrocarbon oil with the desired alkaline earth hydroxide or carbonate, provided the concentration of the sulfonic acid is less than 2.0% and preferably less than If the concentration of the mahogany sulfonic acids in the oil solution is above 20%, neutralization with an' alkaline earth hydroxide or carbonate produces a viscous reaction mass in which the inorganic impurities, such as calcium sulfate and sulfite, are so finely dispersed as to be a colloidal suspension. Such a reaction mixture cannot be economically filtered or centrifuged to -obtain the alkaline earth sulfonates in commercially pure form. It has therefore been found necessary in such case to first produce the alkali metal sulfonates, such as the sodium, ammonium, potassium, etc., which are more easily purified, and thereafter produce the corresponding alkaline earth sulfonates by subjecting the alkali sulfonates so produced to double decomposition, using an inorganic, water-soluble alkaline earth salt. 7 r

I have discovered, however, a novel process to convert the mahogany sulfonic acids in solution in a hydrocarbon oil directly to the alkaline earth sulfonates in concentrations of 20% or higher. concentration of the sulfonic acidsin the oil as produced exceeds 40%, additional oil is added to bring the concentration down within the range of 20-40% by weight for reasons which will be hereinafter developed.

Although this oil is preferably added before neutralization, it may be incorporated at any stage prior to separation and recovery of the system, consisting of hydrocarbon oil and alkaline earth sulfonates as hereinafter described.

In accordance with my invention the mahogany sulfonic acids as obtained by acid treatment of a petroleum distillate or a synthetic alkyl arene hydrocarbon are treated with the required quantity of an alkaline earth base in the presence of an alcohol of l-S carbon atoms. The alcohol used is of 70-100% concentration, preferably As used herein the term In those cases in which the' 80-90. The alcohol should be sufficient to dissolve the alkaline earth metal sulfonates produced and preferably is by volume from 1-3 times the volume of the mahogany sulfonic acids. Alcoholsnupv to and including 5 carbon atoms can be used, but best results are obtained by using alcohols of 1-3 carbon atoms. The effect of the alcohol in the concentrations specified is to insure that the inorganic impurities resulting from neutralization of the sulfuric acid and sulfur dioxide present, will not be present in solution in the alcohol but, pro contra, will be present as insoluble phases.

It is necessary to have suflicient hydrocarbon oil present in the reaction mixture to act as an agglomerant for the finely divided and dispersed inorganic impurities pro duced on neutralization, i.e., the alkaline earth sulfates andsulfites. For thispurpose,ashereinabovestated, the

oil should be present to the extent of from 60-80% of the combined oil plus sulfonic acid, although part.

oil for agglomeration and settling out of the agglomerated impurities. If insufficient oil is present the inorganic impurities remain suspended throughout the alcohol in such finely divided form that their separation by filtration or centrifuging is very difficult. When sufficient mineral oil is present it wets the surface of the finely divided inorganic impurities and causes the individual particles to coalesce into larger units which gravity settle as a bottom layer of oil and impurities. To hasten the coagulating effect I have found mechanical stirring satisfactory but other methods of stir-ring can be used such; After settling the as, for example, blowing with air. upper layer consists of the alkaline earth metal sulfonate together with about one-third by weight of the mineral oil in relation to the alkaline earth metal sulfonate. The bottom layer is semi-fluid and will flow at a slow rate but only through a large diameter opening. This layer consists primarily of the inorganic impurities, such as the alkaline earth metal sulfates, sulfites and excess base, slurried by the added mineral oil. alcohol and alkaline earth metal sulfonates are also present.

Separation of the upper layer and distilling ofi the alcohol therefrom leaves as a residue the alkaline earth metal sulfonates and mineral oil in commercially pure form. They range from gels to rubbery solids at room temperature but become viscous fluids at temperatures above 200 F.

I have further discovered that alkaline earth metal sulfonate oil systems of the type described, which are fluid at room temperature and characterized by much lower viscosities throughout the entire range, may be produced by incorporating small percentages of a water or alcohol soluble salt of an alkaline earth metal intothe alkaline earth sulfonate, either prior to distilling off the alcohol or even to the residue from the alcohol recovery. It is preferably added as a water or alcohol solution and the solvent then removed by any known process to solutize the salt into the alkaline earth metal sulfonate systems.

I have successfully used alkaline earth metal chlorides, nitrates, acetates, formates, but other water-soluble or alcohol-soluble salts can also be used.

If a basic alkaline earth metal sulfonate is desired,- the alkaline earth metal base can be added either alone or in combination with the alkaline earth salt, to obtain Minor quantities of' a basic alkaline earth metal sulfonate of satisfactory fluidity at both ambient and elevated temperatures. This 4 The basic calcium sulfonate thus obtained tested as follows:

effect is illustrated in the f gy g eXamplei Percent Calcium lf t 4 Example 1 5 Percent Calcium hydroxide I; 1.5

Percent Calcium chloride 1.0 it a ig qsa ai iem 39 a had il? t l w percent Mineral Oil 575 Percent Sulfated ash 10.8 Oil-soluble sulfonic acids --P t-- Molecular weight 880 Mineral Oil S.U.S. Viscosity at 210 F 380 Water d n-- Alkalinity mg. KQH/g. 20.0 gig t '.TT""""'ZgZ'II The above shows that this invention may be employed M1016: ul-ar g 425 to produce a basic calcium sulfonate system free from i i undesirable inorganic impurities, of satisfactory fluidity To the above sulfonic acids I added 25% by volume of d possessing th d i d b idt amineral oil distillate of th follow hg test I Other alkaline earth metal sulfonates, similar to the 360 calcium sulfonate describedabove, can be prepared by vis/loo seen 65 using the appropriate alkaline earth base in place of Flash point a 360 calcium hydroxide.

Color-NPA 2 minus Example 3 I prepared the calcium sulfonate by my invention as I formed a slurry of 82 g. of strontium hydroxide in follows: 500 ml. of 80% isopropyl alcohol. I also added 1% g.

500 ml. of 80% isopropyl alcohol was mixe with 50 strontium chloride in aqueous solution. To this I added Calcium hydroxide y The mixture Was sufiicient of the crude sulfonic acids and mineral oil, stirred mechanically and to the stirred mixture I added referred to in Example 1 above to obtain a neutral solul t wnsistillg of about 200 g of the above tion of strontium sulfonate. A purified neutral sulfonate hogany sulfonic acid and about 50 g. of the mineral oil. was obtained upon removal of the alcohol and water.

The acids reacted with the calcium hydroxide to form In a second experiment I added another 82 g. of the calcium sulfonate. The quantity of oil used was strontium hydroxide to neutral strontium sulfonate so found sufficient for the agglomeration and settling of the prepared after removal of the alcohol and before dehydraimpurities, but more mineral oil can be added for this tion. After filtration to remove excess hydroxide and purpose iffound necessary. other inorganic impurities, I obtained the following:

After separation of phases by settling, although centrifuging can also be used, the upper alcohol solution of Neutral Basic Strontium the punfied calcium sulfonate was distilled to remove Test Strontium sulfonate the alcohol and dehydrated to remove water. I obtained sulfonate a product of the following composition: Percent sulfonates 500m 45-b- Percent 011 49.0 41.7. Percent Calcium sulfonate 65 40 lzercentstrontium ghlgrid Percent Mineral Oil 35 Pa anini-shirt: i... at; Percent Sulfated ash 13.95 Al a1i ty- 0 113 mg. KOH/g. Alkalinity 0 iiiiifiiillfiiiifiIjI:::::::::: 2 ml; iili. fluid Molecular weight 880 n I O o Physlcal form gel at 80 mscous fiuld 81200 Similar results were obtained by using other strontium Example 2 water-soluble salts in place of the chloride.

Example 4 To improve the fluidity of the above calcium sulfonate I hi eXpm-iment I used 115 g. f barium hydroxide oil system, I added small percentages of calcium chloride suspended in 500 ml. of 80% isopropyl alcohol. I als'o in the form of a 20% aqueous solution to an alcohol soludd d 2 1 ba i hl id i aqueous solution. I tion of calcium sulfonate so produced prior to removal of h dd h proper quantity f mahugany lf i alcohol by distillation- The calcium sulfonatfi Was acids to neutralize the base, and sufficient mineral oil to luted with mineral oil to a 40% concentration. Upon i glo t th bapium lf t d 1fi f d as im. distillation of the alcohol and dehydration to remove wai i as ib d Previously A purified. neutral woIobtainedthe following products: barium sulfonate is obtained from the settled alcohol solution. m m (my I also made the basic barium sulfonate by adding an Percent Calcium n s equal quantity of barium hydroxide, in water solution,

Chloride added fated F S U S V15 210 to the neutral barium sulfonate produced as given above after the alcohol was removed but prior to dehydration.

3 0 g5] too viscous to The finished Pf q filtration to remove the determine. last traces of insoluble impurities.

fluid gg gg I obtained the following barium sulfonates by the use 12.90 do 2l8sec. of this process:

This demonstrates that small percentages of calcium Test s iiiioii t ei l l ift l il iii chloride change the gel structure of the calcium sulfonate system to that of a fluid of low viscosity. Similar results Percentsmronates 46.1 were obtained by the use of calcium formatc, acetate and Percent 44.0.

Percent barium chloride" 1.0. nitrate. Percent barium hydroxide 8.9.

When excess lime is added together with the calcium Perceptsulfated ash-m chloride to obtain a basic fluid calcium sulfonate, it is figfl fliggig flj 3 3 necessary to filter the product after distillation and de- Physicalfvrmn-n t i fl i dhydration to remove unreacted lime and other impurities.

Similar results were obtained by the use of watersoluble =barium salts in place of the chloride.

Example 5 I prepared the magnesium sulfonate, using magnesium hydroxide for neutralizing the mahogany sulfonic acids and magnesium chloride for reducing the viscosity of the neutral magnesium sulfonate.

The neutral magnesium sulfonate tested as follows:

1. Process for the production of commercially pure alkaline earth metal sulfonates in mixture with hydrocarbon oil which comprises reacting a mahogany sulfonic acid containing in excess of 20% of sulfonic acid in relation to the total sulfonic acid and hydrocarbon oil and containing free sulfuric acid and sulfur dioxide, said mahogany sulfonic acid being produced by the sulfonation of alkyl aromatics of the type contained in petroleum distillates, with an amount of an alkaline earth base suflicient to at least neutralize said sulfonic acid in the presence of an amount of alcohol of not more than 3 times the volume of the mahogany sulfonic acid but sufficient to dissolve the alkaline earth metal sulfonates produced, said alcohol having not more than 5 carbon atoms in its molecule and a concentration of at least 70% the balance being water, thereby producing alkaline earth metal sulfonates in alcohol solution and settling said alkaline earth metal sulfonates in said alcohol solution in the presence of hydrocarbon oil having a viscosity S.U.S. of 30 to 1000 seconds at 100 F. and a specific gravity of from 0.77 to 0.95 to the extent of 60-80% by Weight based on the combined oil and sulfonic acid thereby producing an alcohol phase containing in solution the alkaline earth metal sulfonate and some of the hydrocarbon oil, and as a separate phase, oil and oilagglomerated impurities and recovering a mixture of oil and alkaline earth metal sulfonate from the alcohol phase.

2. Process according to claim 1 in which the alcohol is isopropyl alcohol.

3. Process according to claim 1 in which the alkaline earth metal sulfonate produced is calcium sulfonate.

4. Process according to claim 1 in which prior to recovery of the mixture comprising oil and alkaline earth metal sulfonates from the alcohol phase there is incorporated therein at least 1% by weight, based on the weight of the mixture of an alkaline earth metal salt selected from the water-soluble and alcohol-soluble salts.

5. Process according to claim 4 in which the alkaline earth metal sulfonate produced is calcium sulfonate.

6. Process for the production of commercially pure alkaline earth metal sulfonates in mixture with hydrocarbon oil which comprises reacting a mahogany sulfonic acid containing in excess of 20% of sulfonic acid in relation to the total sulfonic acid and hydrocarbon oil and containing free sulfuric acid and sulfur dioxide, said mahogany sulfonic acid being produced by the sulfonation of alkyl aromatics of the type contained in petroleum distillates, with an amount of an alkaline earth base sutficient to at least neutralize said sulfonic acid in the presence of an amount of alcohol of not more than 3 times the volume of the mahogany sulfonic acid but suflicient to dissolve the alkaline earth metal sulfonates produced, said alcohol having not more than 5 carbon atoms in its molecule and a concentration of at least the balance being water, and in the additional presence of hydrocarbon oil having a viscosity S.U.S. of 30 to 1000 seconds at F. and a specific gravity of from 0.77 to 0.95 to the extent of 60-80% by weight based on the combined oil and sulfonic acid thereby producing alkaline earth metal sulfonates in alcohol solution and settling said alkaline earth metal sulfonates in said alcohol solution thereby producing an alcohol phase containing in solution the alkaline earth metal sulfonate and some of the hydrocarbon oil, and as a separate phase, oil and oil-agglomerated impurities and recovering a mixture of oil and alkaline earth metal sulfonate from the alchol phase.

7. Process according to claim 6 in which the alcohol is isopropyl alcohol.

8. Process according to claim 6 in which the alkaline earth metal sulfonate produced is calcium sulfonate.

9. Process according to claim 6 in which the mixture contains from about 20 to 40% of sulfonic acids in relation to the total sulfonic acid plus hydrocarbon oil.

10. Process according to claim 6 in which prior to recovery of the mixture comprising oil and alkaline earth metal sulfonates from the alcohol phase, there is incorporated therein at least 1% by weight, based on the weight of the mixture of an alkaline earth metal salt selected from the water-soluble and alcohol-soluble salts.

11. Process according to claim 10 in which the alkaline earth metal sulfonate produced is calcium sulfonate.

References Cited in the file of this patent UNITED STATES PATENTS 1,935,666 Ramayya Nov. 21, 1933 2,334,532 Archibald Nov. 16, 1943 2,395,713 Barbour Feb. 26, 1946 2,413,311 Cohen Dec. 31, 1946 2,414,773 Showalter Jan. 21, 1947 2,418,894 McNab et al. Apr. 15, 1947 2,467,176 Zimmer et al. Apr. 12, 1949 2,532,997 Cohen Dec. 5, 1950 2,671,758 Vinograd et al. Mar. 9, 1954 2,713,034 Clarke et al. July 12, 1955 2,738,326 Anderson et al Mar. 13, 1956 2,791,558 Schuessler et al. May 7, 1957 2,848,415 Logan Aug. 19, 1958 FOREIGN PATENTS 493,408 Canada June 2, 1953 

1. A PROCESS FOR THE PRODUCTION OF COMMERCIALLY PURE ALKALINE EARTH METAL SULFONATES IN MIXTURE WITH HYDROCARBON OIL WHICH COMPRISES REACTING A MAHOGANY SULFONIC ACID CONTAINING IN EXCESS OF 20% OF SULFONIC ACID IN RELATION TO THE TOTAL SULFONIC ACID AND HYDROCARBON OIL AND CONTAINING THE FREE SULFURIC ACID AND HYDROICARBON OIL AND MAHOGANY SULFNOIC ACID BEING PRODUCED BY THE SULFONATION OF ALKYL AROMATICS OF THE TYPE CONTAINED IN PETROLEUM DISTILLATES, WITH AN AMOUNT OF ALKALINE EARTH BASE SUFFICIENT TO AT LEAST NEUTRALIZE SAID SULFONIC ACID IN THE PRESENCE OF AN AMOUNT OF ALCOHOL OF NOT MORE THAN 3 TIMES THE VOLUME OF THE MAHOGANY SULFNOIC ACID BUT SUFFICIENT TO DISSOLVE THE ALKALINE EARTH METAL SULFONATES PRODUCED, SAID ALCOHOL HAVING NOT MORE THAN 5 CARBON ATOMS IN ITS MOLECULE AND A CONCENTRATION OF AT LEAST 70% THE BALANCE BEING WATER, THEREBY PRODUCING ALKALINE EARTH METAL SULFNONATES IN ALCOHOL SOLUTION AND SETTLING SAID ALKALINE EARTH METAL SULFONATES IN SAID ALCOHOL SOLUTION IN THE PRESENCE OF HYDROCARBON OIL HAVING A VISCOSITY S.U.S OF 30 TO 1000 SECONDS AT 100 DEGREE F. AND A SPECIFIC GRAVITY OF FROM 0.77 TO 0.95 TO THE EXTENT OF 60-80% BY WEIGHT BASED ON THE COMBINED OIL AND SULFONIC ACID THEREBY PRODUCING AN ALCOHOL PHASE CONTAINING IN SOLUTION THE ALKALINE EARTH METAL SULFONATE AND SOME OF THE HYDROCARBON OIL, AND AS A SEPARATE PHASE, OIL AND OILAGGLOMERATED IMPURITIES AND RECOVERING A MIXTURE OF OIL AND ALKALINE EARTH METAL SULFONATE FROM THE ALCOHOL PHASE. 